Bloom time: The Red Hills azalea starts blooming later usually in May than any other similar azalea, and almost always immediately after the late-blooming Alabama azalea drops its flowers. The coastal hammock sweet azalea and the plum leaf azalea bloom even later, usually in summer, but they look nothing like the Red Hills azalea, and generally don't grow in the same areas.
Bloom color : Bloom color is highly variable perhaps with more colors than any other native azalea and that itself can be a clue. The predominant form has white petals, sometimes with a pinkish cast or a yellow blotch, and typically a pink and white striped tube below the petals. But some forms may be nearly orange or completely pink or completely white. Because the petals are unusually thick, the colors appear opaque and deep, rather than translucent, as would be typical for most native azaleas.
Bloom fragrance: Very sweet, but spicier and more zesty than many other native azaleas. Some have likened the odor to the lemony fragrance of the Alabama azalea, but it is different. It is quite distinct from the musky-sweet narcissus odor of the common pink honeysuckle azalea.
Habitat: Where the plant grows is an excellent way to distinguish it from the Alabama azalea, which can sometimes overlap it in bloom time and appearance. The Red Hills azalea seems to always grow in moist, rich terraces spreading out from streams, on the sandy banks of the streams, or on moist, north-facing slopes. The Alabama azalea, by contrast, seems to be restricted almost entirely to much drier upland areas.
Range: The Red Hills azalea seems to follow closely the limestone and mineral-rich soils of the Red Hills, stretching roughly from Meridian, Miss., southeastward through Clarke, Monroe, Butler and Conecuh counties in south central Alabama to south of Dothan. A few outlying populations seem to grow along similar soils near the banks of the Chattahoochee River in Georgia.
Seed capsules: Scientists often use fruiting, or seed, capsules to more carefully distinguish plants. The seed capsules of the Red Hills azalea are quite distinct from the Alabama azalea, with prominent wart-like features and (if you use a hand lens on fresh capsules) distinctive gland-tipped hairs. These glandular hairs, however, are not nearly as dense as they are on the coastal flame azalea.